Right now, the good ship Red Sox is steaming along, with Boston having flattened its opponents en route to the best record in the American League. Even so, on Friday night, the team had a reminder of an area that will likely need to be reinforced prior to the trade deadline.

Everything, of course, can change at a moment’s notice. As the Red Sox have been reminded in recent days, injuries happen, and carry with them the potential to redefine entirely what the team will want to prioritize adding between now and July 31.

Just in the past two games, the Sox have seen starter Clay Buchholz (back), shortstop Jed Lowrie (shoulder), left fielder Carl Crawford (hamstring) and third baseman Kevin Youkilis (gastrointestinal woe) all leave in the middle of games for a variety of ailments. Yet by and large, the injuries haven’t caused much of a ripple, in part because the Sox have seemingly had the depth to deal with them.

Buchholz’ injury – which will require him at least to be pushed back a couple of days, and could result in him missing a start altogether or even heading on a DL stint – comes at a time when the Sox appear to have some starting depth.

The team was already planning on calling up Andrew Miller. Alfredo Aceves has shown the ability to fill in competently. In the minors, beyond Miller, Felix Doubront and Kyle Weiland are both throwing well.

Moreover, both Josh Beckett and Jon Lester having been dominant in their most recent outings. Tim Wakefield has performed ably since taking over Daisuke Matsuzaka’s starting spot.

Meanwhile, in Friday night’s 10-4 victory over the Brewers, John Lackey (3-0, 5.03 ERA, 6.9 strikeouts and 1.8 walks per nine innings since coming back from DL; 2-5, 8.01, 4.3 and 4.1 before) continued to show signs that the DL stint for his right elbow strain yielded an improved pitcher. Perhaps most notable, against a Brewers lineup that is among the deepest in the NL, he punched out five and walked none in his eight innings.

“I’ve definitely been getting [swings and misses] more,” noted Lackey. “I think that says a lot about how I’m feeling, and that things are getting stronger.”

All of that, in turn, has the Sox in a fairly healthy position with regards to their starting – especially since Buchholz has a 2.79 ERA in his last 11 starts.

Lowrie’s injury – he felt a pop in his shoulder on his swing in Tampa Bay on Thursday and is now on the DL with what the team is calling a strained left shoulder (pending a second opinion on his MRI by Dr. Lew Yocum) – comes at a time when Marco Scutaro is playing his best baseball of the year. He is hitting .355 with an .863 OPS in June, and likely would have been forcing his way into increased playing time even without Lowrie’s injury.

Crawford is in wait-and-see mode regarding what the Sox diagnosed as a Grade 1 hamstring strain in Friday’s contest. Given the degree to which his game depends on his legs, the Sox will undoubtedly proceed with caution.

Certainly, his injury reinforces the perception that the Sox may want to test the waters in the trade market for available outfielders. That exploration that already seemed necessary given the utter lack of an offensive impact being made by J.D. Drew, who has scored just 16 runs and driven in only 18 while hitting .227 with a .660 OPS this year.

Still, as bad as Drew has been, even with Crawford’s injury, the Sox aren’t in a dire position regarding outfielders. They have competent backups in both Mike Cameron and Darnell McDonald. Moreover, their lineup depth – at a time when they’ve scored 10 or more runs in seven of their last 26 games – is such that they can compensate for diminished production at a couple of positions. Outfield is an area where they will be capable of an upgrade on the trade market, but the team's hand need not be forced.

With both the rotation and the outfield, the Sox are likely to be in a position over the remainder of the trade deadline season to make moves based on opportunity rather than desperate necessity. If a player who can help them becomes available at a reasonable price – perhaps someone like Mets right fielder (and free-agent-to-be) Carlos Beltran – they can make a move.

But barring a long-term injury to one of the top five hitters in the Sox lineup (Jacoby Ellsbury, Dustin Pedroia, Adrian Gonzalez, Kevin Youkilis, David Ortiz) or to rotation members Beckett, Lester or Buchholz, the Sox possess enviable depth.

The bullpen, however, is another story. The Sox had a reminder of just how thin their relief corps is on Friday. Jonathan Papelbon was unavailable while serving the first contest of a two-game suspension. Manager Terry Francona was asked whether Papelbon’s absence meant that Daniel Bard would inherit ninth-inning duties.

“Not necessarily,” said the Sox skipper. “Bard is that one weapon, we talk about it so much, he’s always the guy who comes in with men on base. I’d hate to try to get to the ninth inning and stay away from him. If you’ve got a three-, four-run lead with the bases loaded, I’d rather it be Bard [in the game], then we’ll figure out the ninth.”

There was a subtext to that assessment. The Sox bullpen currently features Papelbon for the ninth, and Bard for the game’s most important outs leading up to the closer. Beyond those two, the team is vulnerable.

Neither Bobby Jenks nor Dan Wheeler – the free-agent relievers whom the Sox brought in this winter – has offered bullpen stability. Jenks is on the DL for the second time this year, and he has a 6.57 ERA that is nearly double his career 3.51 mark. Wheeler has a 1.17 ERA since returning from the DL four weeks ago, but he’s rarely being used with the game in the balance while he tries to whittle down his 7.00 ERA.

Matt Albers similarly has a 1.18 mark in his last eight games, and he’s asserted himself as the most trusted setup man beyond Bard. Aceves has a 2.60 ERA in 15 relief appearances this year. Both have performed well, exceeding the expectations that greeted their signing with the Sox. Yet neither has asserted himself as a shutdown weapon.

Overall, the Sox have a 4.09 relief ERA that ranks 22nd in the majors along with a 9-10 record. Papelbon’s suspension served as a reminder that, if one of two pitchers (Papelbon or Bard) goes down, an area of weakness could become a pronounced vulnerability.

That said, the Sox may have some internal options that could change that forecast. Perhaps Albers, Wheeler, Jenks or Aceves will assert himself in the middle innings mix to the point where the Sox’ options multiply. Or, perhaps a pitcher in the minors – Miller, Doubront and Weiland come to mind – can make a case for himself as a late-innings option, especially if the Sox conclude that the cost of relief on the trade market is unpalatable (a conclusion that was reached in 2010, when the Sox shifted Doubront and Michael Bowden to the bullpen rather than pay dearly for relief at the trade deadline). 

But for now, the Sox bullpen has been only marginally better than it was a year ago, when the inability to find a complement to Bard and Papelbon yielded an area of pronounced weakness that the club felt compelled to address during the winter. On a team that is otherwise built to win in 2011, it is a vulnerability that will need to be addressed in the coming months.